Histone acetylation happens in the lysine residues of H3 or H4 and is catalyzed by histone acetyltransferases and histone deacetylases.[24] The specific knockout of Kat8 in the developing brain of mice results in developmental defects in the neocortex and hippocampus, resulting in fewer, lower density, and increased apoptosis neurons in mutant mice; Intellectual disability, autism spectrum disorder (ASD), and other abnormalities exist in patient with Kat8 mutation.[25]. The gene discussed is KAT8; the disease is autism spectrum disorder.